1. Field of the Invention
The present invention relates to a technical field of a disk drive apparatus optimum for application to a floppy disk drive for recording and/or playing back data onto and/or from a disk-shaped recording medium such as a floppy disk.
2. Description of the Prior Art
In the conventional floppy disk drive, it is necessary to mount and remove a disk cartridge. Thus, components such as an upper magnetic head are installed on a member such as a mold part through a thin plate spring known as a gimbal. In turn, the mold part is attached to the cabinet of the floppy disk drive by another plate spring in such a way that the mold part can be moved up and down. In such an installation, the mold part itself may be floated in the circumferential direction of the floppy disk due to causes such as vibration of the plate spring. In the conventional floppy disk drive, however, a mechanism of a pair of upper and lower magnetic heads allows recording and playback operations to be carried out with the magnetic heads brought into contact with the floppy disk due to the fact that a load pressure applied between the upper and lower magnetic heads is large, components including the lower magnetic head is put in an all but fixed state and the upper magnetic head follows the lower magnetic head.
In a floppy disk drive for driving a floppy disk with a large storage capacity, on the other hand, upper and lower magnetic heads forming a pair are each installed on a thin plate spring with a triangular shape known as a suspension like one used in a hard disk drive. The upper and lower magnetic heads are each set by a balance of the weights of the 2 suspensions at a position separated by a distance from the floppy disk. Such a floppy disk drive adopts a driving technique whereby recording and playback operations are carried out with the magnetic heads following slight fluctuations of the surface of the floppy disk.
In such an arrangement, however, it is necessary to install the suspension on a plane on a carriage side opposite to the magnetic head. In addition, the distance of the plane from a disk chucking surface, the parallelism of the plane to the surface and the levelness of the plane must be controlled with a high degree of precision. If the magnetic head is installed on a mold part by a plate spring like the magnetic head of the floppy disk drive, high precision can not be assured since the effect of rolling may exist.
There is also a technique of installation whereby the suspension is attached to the carriage directly without using a mold part, the precision of which can not be assured as described above. Taking the fact that the disk cartridge needs to be mounted and removed on and from the floppy disk drive, however, it is necessary to provide a long suspension. As a result, the resonance point is shifted to a low frequency inevitably, raising a problem of a hindrance to control of the magnetic head.